Scamp 13 Axle

[Brian B-P]

Originally Posted by N and J in VT

Here are some photos of my current axle that I'm looking to replace with seized brake actuators. Please let me know if you need more all pictures are of the drivers side.

Good start...

• Those photos show the axle from the rear. With what I now understand from RogerDat's description of the Scamp configuration, the "interesting" part of the axle bracket is the front part, so could we see that end?
• Edit note: When I first posted this response, there were two photos... now there are three, and the third one addresses the requirement I was explaining below. I'll leave this text to explain why I was asking for the mysteriously appearing third photo...To determine the start angle, we need to see the end of it from the side. The desired photo would be of the same area, but instead of looking forward from behind the driver's side hub area, you would need to be beside the trailer, looking across the trailer (right angle to the direction you are looking in these photos. Ideally the middle of the photo would be that square tube that's part of the axle and runs across the trailer frame behind the hubs.

I note that the bracket of the axle is not properly aligned with the frame. I suspect when we see the other end we'll see that they did this so the front part of the bracket could overlap the structure, but they didn't reinforce the mounting area to properly support the part of the bracket visible in these photos; this is yet another reason I shake my head in wonder at the questionable things found in Scamps...

[RogerDat]

Originally Posted by Brian B-P

I note that the bracket of the axle is not properly aligned with the frame. I suspect when we see the other end we'll see that they did this so the front part of the bracket could overlap the structure, but they didn't reinforce the mounting area to properly support the part of the bracket visible in these photos; this is yet another reason I shake my head in wonder at the questionable things found in Scamps...

Ok time for some Scamp brand loyalty. But you knew that was coming didn't you Brian? Hard to argue with "it worked for the last 35 years" same as mine.

So I guess question yes, questionable? eh not so much.

[Brian B-P]

Originally Posted by N and J in VT

Here are some photos of my current axle that I'm looking to replace with seized brake actuators. Please let me know if you need more all pictures are of the drivers side.

In the photo which displays first (image-3369615104.jpg), you can see a square pattern within the round end of the arm. That's the end of the inner square bar that runs into the outer tube that runs across the frame. The rubber rods are between the corners of that inner bar and the outer tube.

When the axle is in new condition, and not supporting the trailer, the corners of the square bar point straight up, down, forward, and rearward, held there by the rubber rods. When load is placed on the axle and the wheel pushes up on the end of the arm the bar is forced to turn, which squashes the rubber rods. Although this photo isn't level, or taken square onto the bar and tube end, it seems that even with no load on the axle the rubber is staying somewhat squashed, so the bar is turned... that means that the rubber is degraded.

If you draw a line through the forward and rearward corners of the bar, it looks like it would run right down the middle of the arm which goes to the hub. That means with new rubber, and no load on the axle, the arm would sit horizontal... it would start at an angle of zero to the horizontal.

If the start angle were more than zero downward, a line along the middle of the arm would sit at that angle below the line through the bar corners.
If the start angle were more than zero upward, a line along the middle of the arm would sit at that angle above the line through the bar corners.

If my judgement of zero start angle is correct, to return to original height the replacement axle would need a zero start angle, and would need to be installed in the same location, with the same height of bracket.

[Brian B-P]

Originally Posted by RogerDat

Hard to argue with "it worked for the last 35 years" same as mine.

When Scamp did a more extreme version of essentially the same thing on the 16' and 19', but without the bracket lapped over other structure, the brackets ripped, disabling trailers and requiring complete axle replacements. Years of 1500 pound trailers working despite the misuse of an axle bracket (perhaps because it was designed for 2200 pound axle loads) just shows that sometimes you can do bad things and get away with it... that doesn't make it a good thing.

A strip of steel plate welded in to triangulate the cantilevered bracket area would have made it safer... they just didn't bother.

[RogerDat]

Originally Posted by Brian B-P

When Scamp did a more extreme version of essentially the same thing on the 16' and 19', but without the bracket lapped over other structure, the brackets ripped, disabling trailers and requiring complete axle replacements. Years of 1500 pound trailers working despite the misuse of an axle bracket (perhaps because it was designed for 2200 pound axle loads) just shows that sometimes you can do bad things and get away with it... that doesn't make it a good thing.

A strip of steel plate welded in to triangulate the cantilevered bracket area would have made it safer... they just didn't bother.

Did not say good, bad, or better. Just that it worked fine for a long long time. Absent complaints about this configuration failing on this model trailer. No reason for the OP to feel like it's an issue to worry about.

The other problem you mention was a more extreme cantilever, almost all on the side that gets hammered the hardest, on a much heavier trailer with a bolt hole near both a weld and the edges. In that case the brackets poor mounting configuration was compounded by other factors. And yep they certainly screwed that one up. Had they always been built with the bracing you suggest it might have prevented all the other screw ups from causing a failure in that given situation.

Instead they moved the brackets to put the load side under the trailer frame, stopped putting holes at the edge and that was enough engineering to bring it back to a good, if not the best possible design.

Certainly true (as proven by events) you can get away with a design on a 1500 pound trailer that won't fly on a 2500 pound one.

[Brian B-P]

I didn't intend to panic anyone with a Scamp 13'... the oddball factory-stock axle mounting is obviously adequate.

About the 16'/19' axle mess:

Originally Posted by RogerDat

Instead they moved the brackets to put the load side under the trailer frame, stopped putting holes at the edge and that was enough engineering to bring it back to a good, if not the best possible design..

In other words, they just started doing it by the correct and normal method, which is probably what they intended in the first place (they just ordered wrong and didn't catch the error in the factory... for years). This correct configuration isn't just good enough, it is as designed.

[Harvey]

I'm still a little (somewhat?) confused by Roger's repeated reference to having to 'cut' or modify Dexter's factory mounting bracket to fit the Scamp drop floor framework (or have it specially built?). My '85 Scamp 13' had the Al-Ko leading arm 'torsion arm' axle (probably factory). After talking with the Dexter engineer I determined to go with a Dexter #9 'torflex' axle with 7" electric brakes in leading arm, 22.5 degrees down configuration. I also decided to use a 'side mount' kit & high brackets as I wanted the extra 'lift' for towing with my '08 Tacoma 4WD P/U.

The ONLY place the original Al-Ko bracket was fastened to the 'drop floor' framework was on the passenger side about a 1" vertical weld at the front of the bracket to the lower longitudinal floor frame piece, & I believe that was more for benefit of the floor frame than the axle or bracket as that frame piece also has a 'strap' welded from the upper frame piece to the lower on a few inches in front of the axle bracket. I also decided to 'use' part of the existing Al-Ko bracket to mount the side mount bracket kit since the Al-Ko bracket was solid 1/4" angle steel & the trailer chassis only about half that (or less), so we used an Accetylene torch to cut the old axle bracket at the 'L', & to cut the small vertical weld at the drop floor frame piece. In measuring for the new axle dimensions I 'allowed' for the side mount bracket but mainly I just followed the dimensions on Dexter's website & planned to weld the side mount kit directly under the remnants of the old Al-Ko brackets. After using a small grinder to 'dress' the old bracket remnants & the vertical 'frame' weld we simply raised the new Dexter axle (with side mounting kit attached) into place with a floor jack, 'squared' the spindle ends with the trailer coupler, clamped the whole assembly in place with a couple of large 'C' clamps, & 'tack welded' the side mounts in place (to the remnants of the original Al-Ko brackets; there was no need to cut or modify any part of the new axle assembly). We then unbolted the axle from the side mounts, lowered it to the floor, & proceeded to weld the side mounts in place on the old bracket remnants. We did have to cut a couple of spacers to go between the side mounts & the trailer chassis as the new axle brackets sit more forward than the originals & the new brackets are longer in front to correctly put more support at the spindle location. As can be seen in a couple of the pix, the original Al-Ko brackets were 'longer' toward the rear which would have been correct for a 'trailing' arm configuration. Since we essentially 'welded in place' the new bracket/side mount assembly (& I ordered it 'dimensioned' to fit), the new axle brackets slide up inside the side mounts snugly against the 'drop floor' metal on the passenger side, & have about the same amount of space between the mount & the trailer chassis on the driver side. After 'squaring' the spindles with the trailer coupler the new axle ended up almost exactly in the same place against the rear of the drop floor as the original Al-Ko axle, only I now have approx 4-5 more inches of ground clearance & the entry is pretty much a normal step for me. I may hafta devise a small box or platform step for my wife since she's tiny & may have a little difficulty there.

The 'turkey crap' welds have since been re-welded to get better penetration & the entire thing painted with black Rustoleum.